Partial discharge is a localized dielectric breakdown of a portion of an electrical insulation system of a device (e.g., a motor) under high voltage stress. The localized dielectric breakdown can be caused by one or more cracks, voids, or inclusions in the insulation system. A partial discharge can cause damage to the device and indicates that the insulation system is failing, which may further lead to catastrophic damage to the device. Thus, it is desirable to detect partial discharges so that the insulation system may be repaired or replaced before any damage to the device.